In German, when wieistihr ... is used, can Wasihr ... be used instead? What's the difference between wie and was? I am a beginner in German.

wie asks about the state or mode, and was asks about what it is.

The former knows what it is, so ask what it looks like. Such as Wie ist ihr Auto? Ganzgut, Abernuroelviel Gebraucht.

The latter directly asked what it was, such as Was ist ihr Auto? Volkswagen.

By the way, I remembered a joke that the judge asked a suspect, Was ist dein Vater? The answer is Er isst alles. I originally asked what your father does, because it is homophonic, but I answered that my father eats everything. Was ist dein Vater and Wasist Deinvater both use was, one meaning who is your father-what does he do, and the other meaning what does your father eat?

I hope I can help you.